/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: WHY
 * Date: 2022-12-17
 * Time: 20:27
 */
public class TestDemo {
    public class PalindromeList {
        public boolean chkPalindrome(ListNode A) {
            // write code here
            if(A==null){
                return false;
            }
            if(A.next==null){
                return true;
            }
            ListNode fast=A;
            ListNode slow=A;
            while(fast!=null&&fast.next!=null){
                fast=fast.next.next;
                slow=slow.next;
            }
            ListNode cur=slow.next;
            while(cur!=null){
                ListNode curNext=cur.next;
                cur.next=slow;
                slow=cur;
                cur=curNext;
            }
            while(A!=slow){
                if(A.val!=slow.val){
                    return false;
                }
                if(A.next==slow){
                    return true;
                }
                A=A.next;
                slow=slow.next;
            }
            return true;


        }
    }
}
